A New Method to Determine Time Since Death?

There are two significant challenges in any criminal investigation involving badly decomposed or skeletonized remains: who is the victim and when did he or she die?

In the Abbott and Lowell Forensic Mysteries, we’ve dealt with the time since death, or post mortem interval (PMI), issue a few times. In the very first book in the series, DEAD, WITHOUT A STONE TO TELL IT, Trooper Leigh Abbott and Dr. Matt Lowell nearly come to blows when Leigh needs a time since death estimate so she can start looking at missing persons reports, and Matt, a quintessential scientist, refuses to guess when he’s lacking sufficient data. In TWO PARTS BLOODY MURDER, when a skeleton is found immured behind a brick wall, it is Dr. Edward Rowe and his knowledge of history that dates the skeleton. But in LAMENT THE COMMON BONES (out two weeks today!), when a murder victim is found hanging in a forensic anthropology lab, it’s impossible for Matt to estimate the PMI because he’s missing the usual markers—tissue decomposition or bone weathering. The best he can do is to provide a minimum PMI based on the time required to prepare the bones. The maximum can be determined by the last time the victim was seen alive, but that only provides at best a detrimentally large window for a murder investigation. However, a small side storyline involves Dr. Trevor Sharpe, Matt’s scientific arch nemesis, and why Matt hates him so much. In the end, it all has to do with PMI estimates and the extent some researchers will go to in their search for scientific glory.

In the real world, a lack of understanding of PMI started the criminal investigative aspect of forensic anthropology as we currently know it when Dr. Bill Bass misjudged the age of a corpse by over a century (see the fascinating story of Colonel William Shy). As a result, he started the University of Tennessee Forensic Anthropology Research Facility (nicknamed the ‘Body Farm’) in 1981. Since then, research into decomposition in different locations and during different seasons, scavenging, the affect of trauma, entomology, and many, many other aspects of the process of death have elucidated scientific details that have greatly improved criminal investigations.

However, definitive estimates of PMI continue to elude scientists in certain cases, especially those involving skeletonized remains. Without definitive tissue markers, or obvious weathering clues, some estimates around PMI can span months or even years, greatly complicating any criminal investigation. Enter Lincoln Memorial University, Dr. Beatrix Dudzik, and her new project to study bone marrow, the protected inner contents of bones that produce both red and white blood cells. They hope to use the decomposition of lipids within the bone marrow to estimate the time elapsed since death. They are basing their research on a study by Paul Wood and Natalie Shirley where PMI was reliably determined based on skeletal muscle decomposition and the biochemical breakdown products produced up to a year after death. Knowing the difficulties involved in skeletal remains, Dudzik would like to translate a similar breakdown process to bone marrow.

The study will take place at the Body Farm, using twenty donor cadavers over a two-year time period, as well as samples already in the Body Farm’s bone collection with known PMI’s from one to thirty years. The study, which will start in January 2018, will study three types of bones specifically—the calcaneus from the ankle, the tibia from the lower leg, and a vertebrae—as well as teeth to test for lipid breakdown products.

The group hopes that the initial two-year study will produce data allowing for an extension and additional research to better understand this complicated process.

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LAMENT THE COMMON BONES releases two weeks from today and we’ve got a couple of buy links already up for readers who like instant gratification and want their copy waiting for them when they wake up on November 21st. So for e-book readers, we have the following links:

Kindle: https://www.amazon.com/dp/B077721M4V/

Kobo: https://www.kobo.com/ca/en/ebook/lament-the-common-bones

Newsletter readers are getting an advanced sneak peek at the first three chapters of the book today, but come back to the blog next week for a chance to see the exciting opening chapters early!

Forensic Case Files: The Exhumation of H.H. Holmes

We’re ramping up toward the release of Abbott and Lowell Forensic Mysteries #5, LAMENT THE COMMON BONES, so I thought it would be fun to do a forensic anthropology story this week. There was a big story last month that I didn’t review because we were busy with the launch of BEFORE IT’S TOO LATE, but it’s worth covering—the exhumation and the analysis of the body buried in the grave belonging to H.H. Holmes.

For anyone unfamiliar with Dr. Henry Howard (H.H) Holmes, he was a serial killer and con artist who operated against the backdrop of the Chicago World’s Fair in 1893. Holmes, an alias of Herman Webster Mudgett, was born in New Hampshire in 1861, graduated from the University of Michigan’s Department of Medicine and Surgery in 1884, and was a bigamist, at one point being married to three women simultaneously while being engaged to several others.

Holmes settled in Chicago in 1886 and purchased a drug store on a busy intersection in the Englewood neighbourhood. He purchased a lot on the opposite corner from the drug store, designed, and then started construction of a multi-use, three-story building—a drug store on the ground floor with apartments and hotel rooms above that he claimed were part of the World’s Fair Hotel (though there is no evidence they were ever used for this purpose, or even fully completed). His own rooms were located on the third floor.

The upper floors of the building were a nightmarish design of soundproofed rooms, labyrinthine corridors, doors that locked only from the outside, air-tight spaces with installed gas vents, and chutes that transported room occupants to the basement for incineration or to be dissolved in vats of acid. Holmes was ingenious in his methods, even ensuring that no single builder understood the depravity of the building’s design—he would fire workers after short contacts, ensuring that no one ever fully understood the full horror of his plans.

Following the discovery of the building’s real purpose, it was christened ‘The Murder Castle’—a place where people went in, but never came out. Holmes himself admitted to killing twenty-seven individuals, though only nine deaths were confirmed. However, his legend has grown, and some accounts report over two hundred deaths at his hands. What is certain is that several of his paramours/fiancées lost their lives inside the Castle, as well as a number of women who responded to advertisements for employment.

Apart from the lives lost in 1893 during the World’s Fair, it was actually the death of a fellow con artist that finally convicted Holmes. The pair concocted a scheme to fake the death of an inventor in a laboratory explosion and fire. Benjamin Pitezel set up the fake persona and purchased a $10,000 insurance policy. Holmes was supposed to produce a body to be disfigured during the fire, but, instead, he killed Pitezel so he could make the insurance claim without having to split it with a partner. Holmes was eventually caught, tried for Pitezel’s murder, and sentenced to death. He was hanged in 1896.

Earlier this year, a request was made by the Mudgett family to exhume Holmes’s grave to ensure he was buried there. Family legend told that despite Holmes’s request to be buried in a coffin filled with cement and then interred under seven three-thousand-pound barrels of cement to deter grave robbers and infamy seekers, he had escaped execution. The exhumation order was granted and the body was recovered last spring.

Samantha Cox, a forensic anthropologist at the University of Pennsylvania, completed the examination. Due to the method of burial within cement, the body had not fully decomposed. The man’s burial clothes were intact and he still sported a mustache, but the tissues were mostly putrefied but not fully liquefied. Due to the extent of decomposition, DNA could not be extracted from the remaining tissue slurry, but was instead extracted from tooth pulp for PCR and familial DNA profiling. Last month, the results were revealed: the body in the grave of H.H. Holmes was indeed Holmes himself. Despite his wily ways and life of crime, in the end, he was caught and punished. Holmes body was returned to his grave and buried once again.

As a side note, anyone who is interested in more on the life of H.H. Holmes would enjoy the narrative non-fiction novel ‘The Devil in the White City’ by Erik Larson. It’s a well-researched, fascinating account of both the 1893 World’s Fair ‘Columbian Exposition’ and the simultaneous, horrific career of H.H. Holmes.

Photo credit: Wikimedia Commons

Crawling Fingerprints?

Fingerprints have long been one of the cornerstones of forensic crime scene analysis. From their early use in the late 19th century, to their first role in a murder conviction in New York in 1902, to their standard use as we know it today, fingerprints and their analysis have become crucial tools for investigators in their pursuit of criminal justice. Where some other techniques have come into question—such as bite mark analysis—fingerprints have always been considered reliable. There are surfaces that prove problematic, or visualization techniques may not be powerful enough, but the concept of the ability to match a single individual to a single print has never been shaken.

Fingerprints are, in essence, biological traces left by individuals marking their contact with a surface. As Matt Lowell put it in TWO PARTS BLOODY MURDER, a fingerprint is “an organic slurry of amino acids and fats with some inorganic compounds mixed in” we leave behind when we touch a surface. Patent prints are left when a substance is transferred by a finger, leaving a visible print behind i.e. ink or paint. Latent prints are invisible impressions of the slurry Matt describes that need to be processed to be visualized, and are the majority of the prints law enforcement deals with. Fingerprinting can be a difficult endeavor as a pristine, complete print is rarely deposited. Instead, prints overlap, only consist of a partial impression, smear or smudge, or are a mixture of different individuals. Adding to that is the composition of the surface the print is on, the age of the print, and the type of processing involved. It’s a complicated process, but when it works well, the answer is definitive.

A paper was recently released discussing how latent prints change over time, and how they change shape and can actually migrate over certain surfaces. Over time, any fingerprint will lose water content and the bulk of the print ridges will decrease. But it was the placement and positioning of those ridges that was the key to this study.

Some surfaces do not maintain fingerprints well—prints on certain types of plastics will disappear in about four days, where a similar print on glass will remain for months. Porous surfaces such as paper and wood absorb some of the oils and are excellent matrices for locking the print into place. But some materials actually allow the print structure to change as the ridges decrease in height, but increase in width, while the space between the ridges increases. In essence, the print spreads laterally, migrating outward, covering up to 140% of the original surface in just over a week. However, given sufficient time—up to eight weeks—the print will contract, eventually only taking up 69% of the original size.

How does this kind of migration affect a print in a criminal investigation? The authors suggest that this kind of print expansion and contraction could be responsible for a number of the print mismatches that still occur today. They also suggest that if a timetable of migration could be determined, digitized prints could be reverse-aged back to their original structure, which would allow for direct comparison to fresh suspect prints. The authors have suggested this technique would be particularly useful on new polymer banknotes which are already proving a challenge for traditional fingerprinting methods. This technique could prove to be beneficial as it could help investigators overcome a significant problem with fingerprints—a timeline. The presence of a print linked to an individual is a crucial piece of information. But knowing when that print was deposited—yesterday, last week, or last month—could be the difference between a suspect who was in the room at the time of a murder, or a week before, when the victim was still hale and healthy.

Photo credit: Wikimedia Commons

A New Complication in Determining Time Since Death?

In the last few weeks, a few forensics stories have broken, each taking an odd angle on what has previously been considered a tried and true forensic practice. We’re going to look at the first of these stories today.

Determining time since death in an unwitnessed death is a crucial part of any investigation, especially if the death is suspicious. In order to obtain an alibi, investigators need to know approximately when the death occurred so they can determine a suspect’s whereabouts at that specific time.

There are multiple ways to determine recent time since death, including the extent of rigor mortis (the stiffening of the body’s muscles up to approximately 12 hours after death), lividity (the settling and pooling of blood due to gravity), and a decrease in body temperature.

The human body normally functions at 37^oC/98.6^oF, but after death, with the body’s process of homeostasis interrupted, the body will cool until it reaches the temperature of its surroundings. By and large, the body will cool at a rate of approximately 2^oC/3.6^oF for the first hour postmortem, and then 1^oC/1.8^oF thereafter until it reaches ambient temperature. But there are a host of other complicating factors including extreme ambient temperatures, body position, whether it is clothed, humidity levels, fat content of the body, thermal conductivity of the surface beneath the body, and any disease that might raise the body’s resting temperature at the time of death. It’s a complicated set of conditions, but the key factor is that normally a body only cools; it doesn’t warm up after death.

An interesting paper was recently published in the Journal of Forensic Medicine and Pathology detailing a case of postmortem hyperthermia—a rare occurrence where the body temperature actually rises after death. The research team followed the case of a man who died in a Czech Republic hospital from heart failure. Hospital protocol required the deceased remain on the ward for two hours after death. An hour following death, as hospital staff started to prepare the body for transport in another hour, they noticed that the body was radiating heat and started to monitor temperature. An hour and a half after death, the body hit a maximum temperature of 40.1^oC/104.2^oF. Four hours following death, the body was still above normal at 37.6^oC/99.7^oF, but it then continued to cool as expected.

The ramifications of postmortem hyperthermia are clear—if it happened following a suspicious death, it would offset the time since death estimation by a number of hours (in this case, approximately 4 hours). For instance, if a murder happened at midnight, the person found dead at 6am might be assumed to have been alive until 4am. This could have serious repercussions as the killer could have a watertight alibi for four hours after the actual time of the murder, and the window of time around the murder itself would never be questioned. Currently, there is no way to predict this drastic postmortem change in body temperature, but researchers are trying to identify circumstances that might lead to this reverse temperature cascade.

Several causes for postmortem hyperthermia have been raised. Intoxication or drug overdoses may cause it. Violent deaths leading to brain trauma giving rise to cerebral oxygen deprivation or asphyxiation can be responsible. Low voltage current electrocution, heart attack, fever, or cancer can all result in hyperthermia at the time of death which could be mistaken for postmortem hyperthermia. Researchers hope to study more cases to be able to provide additional reasons for this often mysterious condition.

So where does this leave investigators? Should they question every time since death estimate? Postmortem hyperthermia certainly raises the argument that multiple metrics are required to inform investigators of an accurate time since death. Using other physical factors is the only way to ensure that in the absence of a witness, the accurate time of a suspicious death is established, giving investigators their best chance to find the individual responsible.

Of course, the author in me automatically thought this would be a great way to muddy the waters in a fictional murder investigation. Food for thought, mystery author buddies... :)

Canine DNA Profiling

Ann and I are back to blogging now, but we're also shifting back into more forensics-related posts as we're moving toward the release of LAMENT THE COMMON BONES, book five in the Abbott and Lowell Forensic Mysteries. Today, we're looking at a topic that spans our two series as we examine the forensic technique which recently saved the life of a service K-9.

DNA profiling has been used in law enforcement, medical examiners, and archeologists for humans for decades. DNA is used for profiling both victims and suspects in crimes, for identifying the dead after mass disasters, and tracing family lineages through mitochondrial DNA. But the same techniques can be used for other species.

Recently a case came to light of a Belgian Malinois service dog named Jeb who was sentence to be destroyed after he was convicted of killing a neighbour’s dog, Vlad. He was not actually witnessed killing the 16-pound Pomeranian, but he was found by the late dog’s owner standing over the body of the dead dog. While not definitive, it certainly didn’t look good for Jeb. He was taken into custody by Animal Control and a judge was appointed to hear the case. After hearing testimony, including how the neighbour was scared by the large dog because ‘he always barked’, the judge made the reluctant decision to designate Jeb as a ‘dangerous animal’. As a result, he had no choice but to call for the dog’s death.

However the owners, Penny and Kenneth Job, never believed for a moment that their dog was capable of such a violent act. They had adopted Jeb after he’d been rescued as an abandoned pup in Detroit by their daughter, Kandie Morrison. Morrison worked for a local rescue group, but quickly recognized that the young Malinois would make an excellent service dog for her father, as United State Air Force veteran with Charcot-Marie-Tooth, a neurodegenerative disease. With the help of a local veterinarian, Jeb was trained into a gentle, dependable service dog to help support Ken Job and to be there for him if he falls.

The accusation of Jeb being the cause of Vlad’s death didn’t make sense to the Jobs. This simply wasn’t the dog they knew and who lived with three dogs and seven cats in complete peace. Rather than simply taking the heartbreaking news at face value, they took matters into their own hands. While they had previously believed Vlad had been cremated following the investigation, they discovered during the course of the trial that his body was instead frozen. They had argued during the trial that a stray dog had been seen in the area around the time of the killing, and the area was populated with wild foxes, but now they had a chance to scientifically prove Jeb’s innocence. They swabbed the inside of his cheek and arranged for samples to be taken from Vlad’s wounds for comparison at the Maples Center for Forensic Medicine at the University of Florida College of Medicine.

The Jobs were thrilled when the results came back vindicating their dog. Yes, Vlad has been killed by a dog, but not by Jeb. Shortly after, Jeb was released and returned to his loving family and crucially important life of service. DNA had proven his innocence, exonerating him just as it can exonerate innocent human convicts.

DNA analysis is not a regular part of canine cases, even those that call for the destruction of an animal. But the $460 spent by the Jobs definitely decided the case and saved the life of their beloved pet and helpmate. Perhaps it’s time to start thinking about animal cases in the same light—when a life hangs in the balance, isn’t it worth ensuring that justice is being done? $460 doesn’t seem like that high a price to pay to avoid an innocent paying for a crime he didn’t commit.

Photo credit: CNN

Forensic Case Files: The Bard’s Missing Skull

There has been controversy for years about who Shakespeare really was. History tells us he was the son of a glove maker, born in Stratford-upon-Avon in England in 1564, who grew up to be an actor, poet and playwright. But doubts were raised that someone born in a small village and living so far outside royal life would be able to write about it so eloquently, and some have proposed that Sir Francis Bacon or Christopher Marlowe were actually ‘The Bard’. But the man most recognize as the ‘greatest writer in the English language’ is known to have died four hundred years ago on April 23, 1616. He was laid to rest two days later in the chancel of Holy Trinity Church in his beloved Stratford-upon-Avon. Later, his wife, daughter and son-in-law were buried beside him.

Two stories of a strange grave robbing surfaced roughly 250 years later, in 1879 and 1884. They describe a doctor digging up Shakespeare’s head in 1769, possibly to sell to an art dealer. There is a theory from the time that a person’s genius could be discerned from their skull alone, so Shakespeare’s skull would have had significant worth.

Recently, that tale was put to the test as researchers from Staffordshire University were allowed to come into Holy Trinity Church with ground penetrating radar equipment to scan the grave under an etched stone slab. And what they found supports those stories—the results show a disturbance at the head end of the grave showing where dirt was removed and replaced, and the skull does not appear to be present. The scans also show that Shakespeare and his family were not buried in coffins, but simply wrapped in cloth shrouds and entombed in shallow graves, which would have certainly made grave robbing an easier task.

Researchers realize their results ask more questions than they answer, but they are determined to go back to the records of the time to try and solve the mystery of Shakespeare’s missing skull. Was it truly stolen, or could it reside in another church or in a family member’s tomb instead?

An interesting side note to the theft is the epitaph chiseled on Shakespeare’s tomb, one the robbers most certainly ignored:

Good friend for Jesus sake forbeare,

To dig the dust enclosed here.

Blessed be the man that spares these stones,

And cursed be he that moves my bones.

Photo credit:  Steve

Technological Innovations in Criminal Justice

Here at Skeleton Keys, I'm approached on a fairly regular basis by people who want me to help them highlight a program or personal cause. Unfortunately, most of the time, this material isn't directly related to any of our usual topics of forensics, forensic anthropology, writing, or history. But last week, I was approached with an infographic from the Boston University Master of Criminal Justice program. Not only was the infographic a fascinating look at past and current forensic techniques, but it was produced by Boston University—our series readers know all about B.U. as it is the workplace of Dr. Matt Lowell and the location of all the lab scenes in our books. So I was more than happy to share this post with our readers.

Boston University’s Master of Criminal Justice Online Program

Forensics 101: Forensic Toxicology

In blog posts over the past four and a half years (!), we’ve covered many aspect of the forensic study of death encompassing forensic anthropology, forensic pathology, forensic odontology, and including many of the techniques used in crime scene analysis such as fingerprinting, shoe and tire casting, and arson reconstruction. But one topic we’ve never covered that can be a crucial part of any death investigation is forensic toxicology―the analysis of chemicals and biochemicals that may be responsible for a victim’s death.

The body of knowledge required for the complexities of forensic toxicology is extremely broad. Not only does the toxicologist need to be familiar with thousands of toxic chemicals ―including narcotics, poisons, prescribed medications, alcohol, and environmental chemicals―but he or she also needs to understand how each of those chemicals interacts with the human body from ingestion through elimination, including the speed of metabolic processing. Not only does the chemical itself need to be identified, but the concentration must be determined as well, since many legal pharmaceuticals can become deadly poisons when taken in excess. The field of forensic toxicology takes into account aspects and methodologies from a number of sciences―analytical chemistry, biochemistry, epidemiology, pharmacodynamics, pathology, and physiology. It’s a very complicated science.

A toxicologist also needs to consider evidence found at the crime scene including prescription bottles, visible trace evidence, and drug paraphernalia. A half empty prescription bottle near the bed might not mean the deceased took all the missing pills at once, but a syringe of heroin still in a drug addict’s arm might indicate that looking at narcotics would be a good place to start the investigation into cause of death.

Often, however, the original chemical is not what the toxicologist looks for; instead, chemical breakdown products indicate a substance's original presence. And while we are mostly considering toxicology as contributing to cause of death, there are multiple uses of toxicology in live subjects as well, some of which we will consider below.

Multiple human samples can be taken for toxicology testing:

• Urine: While this is one of the most useful, non-invasive samples for drug testing, urine can’t indicate real-time impairment, only prior exposure to a drug. However, it can indicate the presence of chemicals up to several weeks after ingestion. Due to the private nature of sampling, regulations concerning collection must be put in place to avoid sample switching. Urine testing can be used with the living for real-time drug testing (ie. steroid use in sports) or post-mortem to help determine cause of death.
• Blood: As opposed to urine, blood can be used to substantiate the real time effect of a chemical. For example a blood alcohol level of greater than 0.08% indicates a dangerous and criminal level of impairment behind the wheel of a car. Blood testing is often the main way of determining toxic levels of drugs or chemicals in the deceased (ie. carboxyhemoglobin to prove carbon monoxide poisoning during a fire).
• Hair: Hair is used to prove long-time drug usage or to indicate exceedingly high dosages transferred from the blood steam. As human hair grows approximately 1 to 1.5 cm per month, the location of a drug in the hair shaft can indicate ingestion over long periods of time. Unfortunately, the characteristics of the hair itself can affect the results with coarse dark hair retaining more of any compound than fair, light hair, which can lead to suggestions of racial profiling.
• Gastric contents: Depending on the time of death following ingestion of poison or prescription medication, the stomach contents can contain high levels of drugs or potentially undigested pills.
• Vitreous humor: The vitreous humor is the fluid within the sphere of the eye. As it is isolated from the rest of the body, there is no chemical diffusion, and as the eye tends to putrefy more slowly than the majority of the body’s soft tissues, this allows needle sampling and chemical analysis in more decomposed victims.
• Maggot sampling: In victims that are found following a prolonged period after death and are in a state of advanced decomposition, sometimes it is not possible to test the body’s tissues. If flies have been allowed to land on the body and lay eggs, and a sufficient time has passed to allow maggot hatching and feeding, the maggots themselves may contain the toxic chemical that killed the victim. Analysis of the maggots themselves may reveal the chemical cause of death of the victim.

Since multiple sample types and many different compounds must be considered during testing, there are many different complicated analytical chemistry methodologies that can be used for the analysis including chromatography, spectroscopy, x-ray diffraction, immunoassays, and mass spectrometry. Despite the complexities, forensic toxicology can often be the field of science to determine cause of death when many other forensic specialties come up empty handed, leading investigators to a better understanding of the victim’s life and death.

Photo credit: Horia Varlan

Amazing Genetic Tales: Chimeras

A chimera mouse with two of her non-chimeric offpsringA story hit the news last week that was meant to be an interesting human vignette, but the forensic aspects of it immediately jumped out at me. Ah, crime writers. Sometimes we see the world through a special lens!

The story begins with an American couple who conceived a child through in vitro fertilization. The mother carried to term and gave birth to a healthy baby boy. Unexpectedly, however, the boy’s blood type didn’t match either parent, and they became concerned a mix-up had occurred at the fertility clinic. The clinic maintained that on the day of the donation, the father was the only white man to donate sperm; since the child was clearly white, no mix-up had occurred. Still the couple wanted full tests run, so the father contributed a saliva sample and a paternity test was run which concluded that the boy was not his son. Needless to say, the parents were devastated, but they requested a more detailed test through the commercial genetic ancestry company 23andMe.

No one anticipated the results of that test. It was revealed that the man was not the boy’s father, but was instead his uncle. As we’ve discussed in the past, standard identification by DNA is established using 15 markers, but 23andMe uses a genotyping method (near and dear to my heart as we’ve just finished a 5-year Dengue study in the lab based on this technique) called GWAS—Genome-Wide-Association Study—to look at hundreds of thousands of genes for the purpose of building a detailed ancestry map. Because of this extremely thorough analysis, they were able to determine that the boy was the nephew of the man thought to be his father.

However, the man didn’t have a brother. So there was only one conclusion to be drawn from the analysis. Keep in mind the statistic that 1 in 8 single births start as multiple pregnancies, but one of the children is lost very early and, rather than being miscarried, is simply reabsorbed in the womb. Sometimes these cells are then incorporated into the surviving child, making that child a chimera—an organism made up of cells originating from genetically distinct individuals. The man must have been the only survivor of what were originally two fraternal twins, as absorbing an identical twin would have been indistinct from his own natural genotype. As a result, the sperm he produced carried his unborn brother’s genetic signature, but his saliva carried his own. It’s the first known case in the world of a chimera fooling a paternity test.

As a biologist currently heavily involved in complex genetics and genotyping, I was instantly interested in the details of this case. But as a crime writer, I immediately considered the forensic implications of this gentleman. Not that I’m suggesting he’s going to take this information and suddenly adopt of life of crime, but any man with this type of chimerism could be a rapist that would be beyond normal law enforcement’s ability to apprehend since typical DNA sampling techniques would not capture his true genetic state. Luckily, this is a very rare genetic occurrence, and though TV crime shows like CSI might use this scenario as a plot device, the chances of it happening in real life are exceedingly small.

Photo credit: Wikimedia Commons

Forensics 101: A New Technique to Pinpoint Time Since Death

One of the very first forensics posts on Skeleton Keys was about using decomposition to pinpoint the time since death for fleshed bodies. As we mentioned back then, there are some fairly precise ways to measure time since death in first hours following death, up until 24—48 hours post-mortem. But after that, things are much less exact. Needless to say, this can be a problem for investigators who are trying to pin down suspects who need to substantiate their whereabouts with an alibi. But if the best you can do is a 24 hour period, it can be hard for even an innocent person to list all their movements. And what if the investigators are looking at the wrong 24 hour period due to an inaccurate estimate? A more precise way to identify time since death after the immediate post-mortem period would be a welcome tool for investigators.

A team of researchers who recently published in Toxicology Research may have an answer to this dilemma. Their original study set out to examine the changes in 46 biochemical blood parameters to develop a reliable mathematical model to determine time since death. Using 20 normal human blood samples, drawn, aliquotted, and left to coagulate normally, they temperature controlled blood cooling to mimic the typical drop in human body temperature after death—from 37^oC to 21^oC, decreasing 0.5^oC per hour. They then started a kinetic (in time) analysis of the properties of the blood including pH measurements, protein, lipid, enzyme, and electrolyte levels and activity. Of the 46 parameters, ­­­­10 were found to be statistically significant in estimating time since death: total and direct bilirubin, urea, uric acid, transferrin, immunoglobulin M, creatine kinase, aspartate aminotransferase, calcium, and iron. Using these markers, researchers suggest that investigators and forensic scientists will be able to much more precisely pinpoint the time of death out to 11 days after death.

While the results are promising, the authors outline future areas of study as these experiments were done in vitro (outside the body) and under very controlled circumstances. Samples from deceased individuals of known time must also be studied for corroboration. In addition, multiple variables must be considered such as age, gender, body mass, cause of death, and length and type of stress at the time of death. External factors may also play a part—environment and temperature, humidity or precipitation, clothing, or whether the body is buried or left out in the open and possibly infested with insects or consumed by animals. So while there is a lot of research still to do, it’s definitely a very solid starting point from which to launch further research opportunities. Perhaps in a few years, investigators will have a dependable way to identify the time of death of individuals, making their search for suspects a more informed process, hopefully leading to better conviction rates.

Photo credit: Costa et al. in Toxicology Research

Recent Advances in Fingerprinting

While we were on writing hiatus over the summer, several stories made the news concerning advances in the forensic field of fingerprinting. Since they included several new techniques, I thought it would be good to cover them in a single post here on Skeleton Keys, where we always try to stay up to date with the newest in forensics.

Fingerprinting involves identifying an individual by their unique pattern of arches, loops, and whorls on the ridges of the fingertips. Invisible oils and other biomolecules are laid down on a surface, and crime scene techs visualize those scant traces through a number of methods. Those prints are then compared to a local, national or international database and, hopefully, a match is made and a perpetrator is identified.

But a person’s identity may not be the only thing revealed by his fingerprints, as was recently announced:

1. Determining the use of illegal drugs: Researchers from the University of Surrey in England have developed a method to test the residue left in a fingerprint for cocaine using mass spectrometry. More importantly, based on the drug metabolites, it can be determined whether the cocaine was ingested, or whether the suspect simply touched it and traces of the drug remained on his fingertips. New portable mass spectrometers are being developed to make this a technique that can be used in the field at actual crime scenes.
2. Fingerprint Molecular Identification (FMI) technology to identify gender, narcotics and nicotine: North Carolina’s ArroGen Group has developed FMI technology, again using mass spectrometry, to identify gender biomarkers, as well as metabolites of nicotine, heroin, methamphetamine, marijuana, temazepam, ecstasy and even some legal medications. This panel of distinctive chemical substances could lead to suspect identification as well as criminal convictions.
3. Determining the age of a fingerprint: Researchers at the National Institute of Standards and Technology have developed a method to approximate the age of a fingerprint. This has always been a problem using fingerprints as criminal evidence—a print might prove an individual was in a particular location, or touched a particular object, but was it at the time of a crime, or the week before and therefore possibly insignificant? Scientists have tried to develop a method to date fingerprints based on the breakdown of the biochemical products in the fingerprint, but to no avail. However this method is different and depends on the movement of biomolecules from the ridge to the empty valley sections of the print. Essentially the clearly defined lines in a fresh print will blur and become indistinct with time. How much so will help scientists date an individual print. So far, scientists have been able to distinguish between a day and a week old, a week and a month old, and a month and four months old. This is still a proof-of-concept method, but researchers are working to fine tune the technique, which could be incredibly useful in criminal investigations.
4. Determining race of an individual: We’ve previously discussed how to determine race from a victim’s skull, but researchers from North Carolina State University recently announced a technique to determine race from the minutiae of the fingerprint. In a nutshell, there are three levels of examination for a fingerprint. The first level is the one most people are familiar with—those ridge formations called arches, loops, and whorls shown in a standard ink print. The second level is the minutiae—the deviations of those arches, loops, and whorls—where a ridge ends, when it splits in two at a bifurcation, or where the ridge makes a U-turn in a loop or whorl. In comparing those from African-American and European-American backgrounds, researchers found significant differences at the minutiae level, enough to be able to determine from which group the individual came. The study only involved 243 subjects, so these are very preliminary results, but so far the data appears promising.

It is early days so far for many of these techniques, but, with additional study, hopefully they will develop into full-fledged tools for investigators, providing them with more information and hopefully leading to more definitive suspect and victim identifications.

Photo credit: Wikimedia Commons

How to Identify a Suspect… By His Microbes?

There are many established ways to identify a criminal suspect after the fact—DNA or fingerprints, for example (but not bite marks). But in 2010, a theory was introduced that a person could be identified by the bacteria they carried on their skin. The idea is that each person’s specific mix of microbes (called their ‘microbiome’ in scientific circles) is so individual that it could uniquely identify them.

Let’s back up a step because some of you are probably thinking Yeeeccccchhhhhhhh! I’m carrying WHAT on me? Actually, the bacteria that we always carry on us are an important part of our biological stability and are genuinely good for us. While the microbes that live on us make up only approximately three to five pounds of our total body mass, because they are so much smaller than our somatic cells, they actually outnumber our cells by approximately 10:1. In fact, there are enough bacteria that live on us that if we could collect them all, they’d fill a large soup can.

We’re born essentially microbe free, but breastfeeding is the first important transfer of good gut bacteria to newborns. By the time we are adults, it’s estimated that well over 500 species of bacteria live in our gut. These are symbiotic bacteria, meaning they live off us, but we reap the benefits of them in return. We provide a food source for them, but they help us digest our food and better obtain nutrients from our meals. Gut bacteria also help maintain our mucosal immune system making us healthier. Just look to your nearest grocery story or pharmacy for probiotics or probiotic yogurt sold to supplement your natural gut flora. This is exactly why it’s become a significant industry in recent years.

But what about the bacteria that live on your skin? The skin is the body’s largest organ and is our first line of defense against pathogenic invaders. But we’re not alone in the fight—a diverse panorama of bacterial flora live on our skin. Some bacteria help protect us by producing antimicrobials to kill pathogenic bacteria, while others work with our cells, actively using substances we produce to kill invaders. Because the skin is a varied environment with a multitude of cells, glands, follicles, natural moisture levels, and layers of epidermis, we are host to a wide range of bacteria that each live in their own preferred environments. It is these bacteria that give us a unique microbial fingerprint.

This fingerprint is analyzed by identifying the DNA sequences of the bacteria an individual carries. Most individuals host a similar complement of types of bacteria, but it is the relative amounts of these hundreds of strains that constitutes a fingerprint. So each time you touch an object and leave an oil and amino acid slurry fingerprint, you also leave a microbial fingerprint behind. The more commonly used the item, the stronger the microbial fingerprint, with cell phones, keyboards, and shoes bearing the strongest signal. A theory exists that since we leave a bacterial trail behind as we move through the environment, it might be possible to trace a suspect by the trail left by his shoes. It’s even been suggested that a forensic trail left at a crime scene might remain intact for up to two weeks, a very significant period of time in any investigation.

Much study must be done before an individual’s microbes could be used as a forensic tool during a criminal investigation. Previous experiments have been done on groups between two and one hundred and twenty individuals, so the power of this technique can only lie in a specificity that could eliminate millions of individuals to match the power of DNA profiling or fingerprinting. But it’s an intriguing possibility and one that can only expand as studies on the human microbiome, a relatively new field, expands into new and exciting territory.

Photo credit: Wikimedia Commons

Forensics Under the Microscope: Bite Mark Analysis

In our continuing series on forensics run amok, we’re going to look at the trials and tribulations of bite mark analysis as a forensic tool.

What is bite mark analysis? It’s the comparison of a suspect’s dentition (teeth) to a bite mark found at a crime scene in human flesh or another solid substrate. This type of analysis tends to be associated with rape, murder, child abuse, and animal-related infractions because of the nature of the crimes involved. The underlying assumption of bite mark analysis is that human dentition is unique and human skin (or other material) can be imprinted in a way to reflect that uniqueness. The analysis depends on imperfections and deviations such as tooth alignment, chips and broken teeth, tooth wear, dental work, braces, and ethnically-correlated tooth shape to make each set of teeth unique.

How is bite mark analysis done? The first thing any bite mark analyst must do is ensure that the bite is human, and not left by an animal. Measurements are taken of the wound to mark orientation, depth and size of the bite, and then photographs are shot to preserve the bite before any degradation or alteration (decomposition in deceased victims, or wound healing in live victims). Plaster casts can be made of the impression for later comparison with a suspect’s dentition. Sometimes the skin containing the bite mark is excised from deceased victims and fixed in formaldehyde for long term storage and/or later analysis.

How is a match made? When a suspect is apprehended, a plaster cast is made of their teeth for comparison with the bite mark. A forensic dentist will attempt to compare the suspect’s dentition to the bite mark or a photo of the bite mark.

Why is bite mark analysis not a reliable science? The first thing to note here is that many of the scientists doing bite mark analysis are excellent forensic dentists truly trying to assist in case investigations. But the biggest strike against this kind of pattern matching is that there is no scientific proof that the guiding principal―that each person’s dentition is truly unique―is correct. No large population studies have been conducted to answer this question, as opposed to fingerprints or DNA profiling, where the results are truly individual. Therefore, the guiding principle of the technique is based upon an assumption. In actuality, the analysis is the subjective opinion of the technician, based purely on his or her own experience. To make matters worse, the shape of each bite depends on multiple circumstantial factors that can heavily influence the analysis―the force applied during the bite, the substrate, if the subject or substrate is in motion, and the angle of the bite.

What are the problematic technical issues of the analysis itself? There are many technical issues which can influence analysis, such as:

• Tooth wear patterns that change over time—in older cases, current dentition might not reflect dentition when the crime was committed.
• Unlike fingerprints or DNA, there is no dental database for reference.
• Bite marks change significantly over time and decomposition following skin slippage/desiccation.
• Sometimes bodies are exhumed months after burial, producing an imprint that is not identical to the fresh bite. Several of these cases have resulted in convictions.
• Some analysis is done using photos of the bite. Once such analysis noted a gap in the dentition that matched the suspect. The forensic expert recanted a decade later, saying the gap was a flaw in the photo. Nevertheless, this conviction was not overturned.

What are the judicial ramifications? In 2009, the National Academy of Sciences made the damning statement that the forensic science of bite marks had “no evidence of an existing scientific basis for identifying an individual to the exclusion of all others.” According to the Innocence Project, there have been twenty-four people exonerated by other evidentiary means (usually DNA, often not a tool available at the time of the trial). It is estimated that there are hundreds of other prisoners, including fifteen persons awaiting execution, who could be exonerated if bite mark evidence is overturned.

The science of bite mark analysis remains a controversial one, and current forensic investigators always try to find another way to use bites as evidence, i.e. swabbing for the presence of DNA. It is worth noting that not all forensic dentistry is questionable; using dentition to identify human remains is a well-established and successful method in the eyes of both the scientific and forensic communities.

Photo credit: Surlygirl

Forensics Under the Microscope: The FBI and Hair Analysis

Ann and I are in the process of switching writing gears from our current Abbott and Lowell series to our new FBI K-9s series. So when a story recently broke that combined the forensics of one series and the organization of the other, it caught our attention. And what a story it turned out to be. We’re going to be starting a new series of blog posts this week as a result: Forensics Under the Microscope—what happens when the science of forensics goes wrong. Needless to say, the ramifications are enormous.

The FBI story concerns their use of hair analysis in criminal investigations and prosecutions. But before we get into that, let’s start with the technical basics—what is hair analysis and how is it used as part of forensics?

What is the structure of a strand of hair? Hair is actually made up of a number of components, but we’re going to look at the main three: the medulla—the middle or marrow of the shaft; the cortex—the thickest part of the shaft which also gives the hair colour; and the cuticle—the scaly outer layer comprised of dead cells.

What is compared? When crime techs go through a scene, they collect trace evidence, including hair and fibers. When a suspect is arrested, investigators will take various samples from the suspect, including strands of hair. The hair is first examined macroscopically for colour, coarseness and curliness. It is then examined microscopically at up to four hundred times magnification, and the structure and characteristics of the hair are compared side by side in the same field of vision as hairs found at the crime scene (see above photo).

How is a match made? Microscopically, the crime scene hair and the suspect’s hair are compared to match diameter, characteristics of each structural section, and colour variations. A match upon several criteria may be considered a positive result. But unlike fingerprinting, which in its early days had a set number of points that had to match to be considered a positive result, hair analysis depended more on the analyst’s subjective opinion about colour and texture with no minimum number of matching characteristics. Worse still, two examiners might not come to the same conclusion about a single comparison, but the testifying analyst would still have the final word. Finally, the science of hair analysis came into question since there was very little population-specific data about hair traits—i.e. how often a certain trait could be found at random in the general population. As a result, outrageous probability claims (i.e. a one in a million match) were declared during court testimony with absolutely no supporting data.

What happened at the FBI? It was recently reported that the FBI admitted to twenty years of overstated hair analysis evidence in favour of the prosecution. During the 1980s and 1990s, 26 of 28 analysts from the microscopic hair comparison laboratory gave erroneous statements concerning evidence, often overstating the reliability of the technique and the probability of accurate matches. Out of a possible 2500 cases spanning 46 states during that time period, 268 convictions involved hair analysis. Of those convictions, 257 or over 95% of the cases are affected by these erroneous or exaggerated analyses. Of those 257 convictions, 38 suspects were sentenced to death and 9 of these individuals have already been executed, while 5 more died during incarceration. In addition, 13 crime lab examiners mishandled these cases, often not informing defendants that their convictions might be in question.

Is hair analysis still used today? The FBI recognized more than a decade ago that there were problems inherent in the technique, and stopped using it early in 2000. At the time, FBI Unit Chief Douglas W. Deedrick said that the “experience, training, suitability of known hair standards, and adequacy of equipment” could all affect the reliability of the analysis. Another issue raised was that some analysts considered certain microscopic characteristics so unique in hair samples that if the sample partly matched only on these microscopic characteristics, that would be considered a full positive match. Yet there was no population data to support this opinion.

Some consider fingerprinting to be too subjective and prefer definitive evidence such as DNA identification. Yet hair analysis is even more subjective and, as an identification tool, was compared by Deedrick as being no more useful than the ABO blood matching system. A match might steer the investigation towards a group of people, but it should never identify a specific suspect.

What’s the bigger picture and the result of this reveal? Does this mean that all convictions affected by this flawed analysis will be overturned? Of course not; other evidence in the cases may have been strong enough to have convinced the jury without the additional hair evidence. But every case must be individually re-examined.

It’s a story we’ve seen before and that we’ll look at more closely in the future—departments that are part of, or associated with law enforcement organizations, whose employees feel obligated or are externally pressured to support that organization, despite the actual laboratory findings. For any scientist, this is a horrific thought. As I’ve often told my graduate students, your results are your results; they’re not wrong, they simply are. And you shouldn’t bend them to fit your hypothesis. If they don’t fit, then your hypothesis is wrong.

The larger picture here is not scientific results per se, but rather their downstream effect and the lives changed, often forever, because of them. For those looking for more specific information, the Washington Post has published a detailed breakdown of the cases involved.

The U.S. federal government has made the decision to waive the statute of limitations in all of the involved cases and will do DNA testing (not available at the time) in the hopes of conclusively confirming or overturning the convictions. For many involved, it’s much too little, much too late. But hopefully for some, it will be a chance to try to pick up the lives stolen from them so many years ago.

Photo credit: University of Rhode Island

Coming up on Saturday, May 2nd, it’s the inaugural Canadian Authors for Indies Day! I will be appearing on Saturday at 4:30pm at A Different Drummer Books in Burlington, ON (address below) with a roster of very talented authors. So if you’re in the area and would like to stop by and show a great indie bookstore how much we still need them and how important they are in our community, I’d love to see you that day. And if you’re not local to me, but still want to show your supports, please stop by one of the participating indie bookshops listed on the website!

The Serial Podcast

Ann and I must have been under a rock during the late fall of last year because we both managed to miss the original airing of Serial, a new podcast from the creators of NPR's This American Life. It came to my attention after Christmas through one of my Feedly blogs and immediately intrigued me. I downloaded all 12 episodes to my iPod, but then didn’t have a chance to get to it for a couple of weeks. But once I got started, I binge-listened to the entire series—nearly 12 hours long—in three days because I was hooked.

Ann and I are big on research (HUGE understatement there) so the podcast as a whole was fascinating from a process standpoint. Journalist Sarah Koenig, a producer of This American Life, researched and hosted the program. During the course of her research, she was granted access to not only the case records and photos through the Freedom of Information Act, but also audio records from police interrogations and from both trials (the first ended in a mistrial). Many of those clips are included in the podcast, giving the listener the effect of being immersed in the case as it progressed. Ms. Koenig and her team followed old leads, rechecked stated alibis, researched 1990s architectural plans, and even drove the route driven by the suspect that day to confirm timetables. It was a very in depth analysis of a single case.

This is the true story behind the podcast: On January 13, 1999, eighteen year-old high school senior Hae Min Lee disappeared in Baltimore, Maryland. She was last seen at Woodlawn High School, but both she and her Nissan Sentra went missing after leaving the school. She was supposed to pick up her six year-old niece, but she never arrived. On February 9, her body was discovered, buried in a shallow grave in Leakin Park. She had been manually strangled.

Three weeks later, seventeen year-old Adnan Syed, the ex-boyfriend of the victim was arrested for first degree murder. The case was put together based almost solely on information gleaned from police interviews with a friend Adnan spent the afternoon with, and cell phone call records from that day. They even determined the time of death based on those call records—Hae was killed during a 21 minute interval during the afternoon. The friend, Jay Wilds, reported that Adnan had shown him Hae’s body in the trunk of her own car after strangling her in a Best Buy parking lot. He also said that he helped Adnan bury the body in Leakin Park. It was Jay that led police to Hae’s car, weeks after her death and after her body had been recovered. When the case went to trial, Adnan was convicted of first degree murder and sentenced to life in prison.

One of the great challenges of the program is the time elapsed since the events. People were asked to recall back fifteen years to events that happened in 1999. I don’t know about you, but often I have trouble remembering what happened at a specific time last week, forget about more than a decade ago. Most people had to admit that unless there was something specific that happened that day to make it stand out, memories of that time were vague and consisted of details like ‘I’d usually be in class at that time’. Adnan himself admits that he isn’t sure of his exact whereabouts that afternoon.

An interesting aspect of the podcast series was that it wasn’t recorded and then aired. They were working on later episodes as earlier ones were airing. Because of this, people who were familiar with the case or were personally involved started to contact the producers. Some of these were people who had never been contacted by police and had new information to contribute.

There were several areas of the case that certainly left the listener feeling as if they were not getting the whole story. For instance, a classmate of Adnan’s reported seeing Adnan at the library next door to the school during the 21 minute window when he was supposedly murdering Hae. If so, it's a physical impossibility that he could have crossed town to the Best Buy location and committed the murder. But did Adnan’s lawyer ever contact this classmate to bring her in to testify at either trial? She did not. Also, there is the matter of Jay’s constantly changing story to police. Each time they brought him into interview, his story changed—some aspect of where they went that afternoon appeared and then disappeared from the narrative, or the location of important actions, like Adnan showing Jay the body, changed with each telling. When Ms. Koenig drove the route Jay testified he and Adnan had taken the afternoon of the murder, the locations didn’t match the cell phone calls that took place at the same time (based on the physical location of towers pinged during each call). In my mind, this makes Jay about the most unreliable witness possible, yet the entire case was built upon his version of the story told during trial.

As someone who is interested in forensic science, the aspect of the case that horrified me most was the lack of evidence to support the case. The entire case rested on Jay’s testimony tied to records of cell phone calls from the afternoon. But while samples were taken from the victim, DNA testing was never done. DNA samples were taken from under the nails of a victim who died by manual strangulation while likely struggling for her life, and it was never tested for evidence of the killer's identity? Even a rape kit was done and while they tested for the presence of sperm, they never actually tested for DNA. Considering the lack of sperm, any DNA recovered would likely only belong to Hae, but it should have been tested regardless. Hairs were taken from the victim’s body, macroscopically compared to Adnan’s and found to be a mismatch, and then never pursued further. A liquor bottle was found near the body and collected. But it was never tested for DNA, something that might have pointed them toward a different killer, or confirmed the suspect they had in custody. This was 1999, well after the O.J. Simpson case; DNA testing was not new at the time. There’s no reason why this evidence was never explored.

As the podcast series ended, to the surprise of many listeners, there was no dramatic reveal or the unveiling of an alternate suspect. One of the police consultants the producers brought in described the case as ‘a mess’ and that was how it remained. There was no conclusive evidence one way or the other to exonerate Adnan or confirm his guilt. Many listeners were unhappy with the close of the podcast, but this is real life in the legal system—sometimes a case doesn’t have a neat ending tied with a bow like you see on TV.

As a result of the podcast and the attention it drew, the case is now in the hands of The Innocence Project, a group that works to exonerate innocents who have been convinced of crimes. They claim there is another suspect outside the investigation who might be responsible. Ronald Lee Moore had been in prison in Baltimore for sex crimes in 1999, but was released from prison just days before Hae disappeared. DNA samples previously collected from Moore, who killed himself in 2012, will be tested against the DNA evidence taken from the victim. Other suspects will also potentially undergo comparison DNA testing. They will also look into the possibility that Adnan’s lawyer, suffering from MS at the time (she has since passed away), botched the case. So the story of Hae Min Lee and Adnan Syed may be far from over.

Did any of you listen to the podcast? If so, what did you think?

Forensic DNA Phenotyped Facial Imaging

On January 9, 2011, in Columbia, South Carolina, Candra Alston and her three year-old daughter Malaysia Boykin were brutally murdered. When no one heard from them in over three days, Candra’s father went in search of his daughter and granddaughter and discovered their bodies inside their own apartment. A computer, an expensive designer purse, and some children’s clothing were the only missing items. There was no sign of forced entry, leading the police to believe that Candra had known her assailant. There were no eyewitnesses to the crime and very little evidence was recovered from the scene. Police have released few details about the crime regarding the types of evidence or even the method of death beyond describing it as an “extraordinarily violent manner”.

Candra had a wide circle of ‘in real life’ and virtual friends over several social networks. Columbia police have interviewed hundreds of people from South Carolina and a number of other states. Over one hundred and fifty DNA samples were taken from possible suspects. Unfortunately, not one of the possible suspects has matched DNA recovered from the scene. More than three years after the fact, the case has officially gone cold.

But this past week, the case took an interesting twist. Enter Snapshot, a brand new, cutting-edge technology created by Parabon Nanolabs with funding from the U.S. Department of Defense. Snapshot is a new tool not only for law enforcement, but also for national defense organizations. Dr. Ellen McRae Greytak, the director of bioinformatics at Parabon, likens the technology to a DNA blueprint as opposed to the DNA fingerprint of typical sequencing.

Snapshot analyzes the DNA of a given sample, looking specifically at known gene sequences that affect our appearance, and then compares those specific sequences against a database of 10,000 subjects of known appearance. From these complex algorithms, Snapshot is able to produce a virtual likeness of an individual based on their DNA in a process called ‘forensic DNA phenotyping’. It not only predicts ancestry (even if mixed), but skin, hair and eye colour, face shape, and even the expected amount of freckling. The picture above was released only a few days ago by the Columbia, South Carolina police, revealing a potential representation of the suspect in the Alston/Boykin slayings. This is truly groundbreaking technology.

Currently, Texas is the only state to allow forensic DNA phenotyping. As often happens, acceptance of groundbreaking technology comes with skepticism and caveats. Foremost is how accurate the results are if this type of evidence is being used in criminal cases. The image to the right shows an example of one of the database subjects, both the virtual prediction based on the analysis of her DNA and her actual picture. While not exact, it’s a fair representation of the subject, enough in a criminal investigation to delve deeper with established gold standard techniques like DNA profiling.

Where Snapshot is at it’s most useful is through exclusion. Looking at the same image to the right, you can see that it has the highest statistical confidence in excluding the groups the subject does not belong to. Even if the system does not give a 100% accurate estimate of the suspect, just knowing who he/she is not still gives law enforcement an immense investigative lead by narrowing the suspect list and allowing investigators to concentrate on more likely individuals. Imagine a killer leaves skin cells under his victim’s nails during an attack. Given a set of exclusions, it might be determined that the killer was a male of Southern European decent with olive skin, black hair, and brown eyes.  This kind of information would progress a case by leaps and bounds in the absense of an eyewitness to the event.

The virtual estimation of the man above was released by the Columbia police in hopes it would generate additional leads. Time will tell, but with a little luck, maybe Candra and Malaysia will find justice after all.

Photo credit: Parabon Nanolabs and the City of Columbia, SC Police Department

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Forensic Case Files: Jack the Ripper Finally Identified?

Apparently this is debunking science month here at Skeleton Keys. Last week, we looked at the bad science that led archeologists studying the Viking invasions of England to incorrectly identify the sex of buried remains. This week, I want to talk about the recent announcement that Jack the Ripper has been identified more than 125 years after the final murder took place. Several people asked my opinion on this case, and while I’m not an expert on Ripper mythology, I’m happy to tackle the scientific aspect of this announcement.

On September 6^th, a story broke on the Daily Mail naming a Polish hairdresser, Aaron Kosminski, as Jack the Ripper (read the original story here). Russell Edwards, a self-appointed ‘armchair detective’ purchased a shawl supposedly found with the body of Catherine Eddowes, the fourth Ripper victim discovered on September 30, 1888. He approached Dr. Jari Louhelainen, a senior lecturer at Liverpool John Moores University, in hopes of recovering forensic evidence from the scarf to connect the killings to Kosminski. Kosminski had been one of the six main suspects at the time of the murders and Edwards ‘became convinced Kosminski was our man’. (Jen’s note—please keep in mind my opening explanation from last week’s article on the Viking shieldmaidens about how objective science proceeds. Convincing yourself of the end result before you begin is not a good start).

Upon examining the scarf. Louhelainen found traces of blood splatter and semen. Louhelainen extracted DNA from both using a supposedly novel technique called ‘vacuuming’, and, once again, mitochondrial DNA was used to determine the genetic line of the sample. A female descendant of Eddowes provided a DNA sample for comparison and was a perfect match to the blood spatter. A similar descendant of Kosminski (a mysterious, unnamed female whom Edwards claims to be protecting by leaving in anonymity) provided a sample which also resulted in a perfect match to the semen sample.

On this data alone, Edwards declares that Kosminski must be Jack the Ripper.

So where does this claim go off the rails for me?

• The DNA was identified by a novel technique, one that has never been vetted or peer-reviewed in any way (although Louhelainen’s layman’s description of the technique is so basic that there must be more to it than simply soaking the fabric in buffer and sucking it back out again; that hardly seems like a novel technique as it’s fairly close to how we extract cheek swab DNA from filter paper). So where is the proof to the scientific community that this protocol actually does what Edwards claims? Scientific data is rigorously examined through a the process of peer review—a paper is written for an established scientific publication, then that paper is reviewed by fellow scientists in the field who will either accept the paper with revisions (I have yet to see a paper that doesn’t have even a few small comments on aspects to be fixed) or reject the paper. When that paper is published, it has been written with a Materials and Methods section so detailed that anyone reading the paper should be able to exactly replicate the procedure to get the same results given identical starting materials and conditions. But instead of Louhelainen writing a peer-reviewed article on the technique and its results, Edwards has written a layman’s book with no oversight to the scientific process. I can’t believe results only viewed by a privileged few. The entire study cannot be published as ‘data not shown’.

• Assuming this is a legitimate technique, it has tested the DNA found on the shawl of one of the five victims only. This only proves contact with one of the victims and doesn’t scientifically link him to any of the others.

• While the victim’s DNA was extracted from blood, Kosminki’s DNA was extracted from semen. This proves sexual contact of some kind, but in no way actually puts the knife in his hand. For all we know, when Kosminski left Eddowes following that encounter, she was alive and well. The DNA evidence also provides no information about timelines—the sexual encounter could have been minutes, days, weeks, or months before or after Eddowes’ death.

• At the time of Eddowes’ death, Kosminski lived with his two brothers, both of whom would have had identical mitochondrial DNA from their mother. So perhaps it was not Kosminski’s semen, but instead, that of one of his brothers?

• Kosminski’s descendant seems to be shrouded in mystery and apparently Edwards (and the descendant?) wish it to remain that way. As a result, no one else could possibly double check the results of the testing since they have no sample with which to compare the DNA extracted from the semen sample.

• Call me cynical, but I'm suspicious of any science that comes out as a ‘perfect match’. Science almost never works out that way. Yes, mitochondrial DNA only passes down through the female line, but, over time, DNA naturally mutates and drifts and it is unlikely that 125 year old DNA would be identical to a modern sample. Within a 97 – 99% match, absolutely. But a perfect match? And to have two perfect matches, one to Eddowes’ descendant and another to Kosminski’s? Well… you get my drift. Science is simply not that exact. And once again, we can’t see the results ourselves to have a real opinion on it.

• The Daily Mail article shows the scientists at work in the lab. Now, I realize this is an inside baseball kind of point, but I work down the hall from the lab of Dr. Hendrik Poinar, a world famous ancient DNA specialist who not only sequenced the Woolly Mammoth genome, but is currently working on Black Plague deaths in an effort to identify Y. pestis as the causative agent. I know the conditions his people work under—an ultra-clean room under negative pressure and enhanced personal protection (to keep the samples clean vs. protecting the lab worker in this case). Yet Louhelainen and his people are shown unrolling the scarf in a typical biosafety level I wet lab, next to an unrelated specimen and other various pieces of lab equipment and anatomical models. Add to this the fact that the scarf was handled by many people over the years (and supposedly never washed) and I’m not convinced that any starting material they collected was uncontaminated.

• The provenance of the shawl itself has been called into question. Supposedly found at the scene with Eddowes’ body, it was never reported or entered into evidence. Instead, one of the investigating officers removed the bloodstained shawl to give to his wife as a gift. The wife was so horrified by the gift that she put it away and it was then handed down through four or five family generations before being sold to Edwards. But there is no official record of it ever being part of the original murder scene.

My biggest problem with this whole announcement—besides actually naming Kosminski as the Ripper when there is zero proof that he killed even this one woman—is the lack of data. Science works as a transparent system. Show me the DNA gels and then I’ll maybe be on board, but only as far as a DNA match goes. As far as I’m concerned, the identity of Jack the Ripper remains undetermined.

Photo credit: Wikimedia Commons

Forensic Case Files: Viking Shieldmaidens, or How Forensic Anthropology Changed Our View of History

Nineth century Viking burial with sword and knife from Memorial Park, Islandbridge; Dublin, Ireland.It’s not very often that I rant about science, but, oh boy, the story that caught my attention this past week totally set me off. As a career scientist, my day job is all about having a hypothesis and then setting out to prove (or disprove) it. Sometimes you don’t get the results you thought you’d get, but, as I tell my grad students, your results are your results. They’re not wrong, they just are. If you included all of the appropriate controls and conducted the experiment properly at least twice, then this is the truth of the science. You don’t convince yourself of something; instead, the data leads the way to the study’s end result. This is how objective science works. Period.

Recently, researchers at the University of Western Australia decided that previous research teams weren’t being specific enough in their study of Viking remains. The research concerned graves found in England dating back to Viking invasions prior to the 10^th century. It was believed that the overwhelming proportion of Vikings migrating to England at the time was male, with only a very few females in the party, often identified as camp followers. But personal and place names from the area as well as modern mitochondrial DNA relating back to that time implied that there must have been more women present than originally thought. Shane McLeod (currently at the University of Sterling) decided to study that disconnect more closely.

Previously, when examining remains within Viking graves, archeologists sexed the occupants simply by their grave goods—the presence of buried weapons indicated male remains, while females were identified by a traditional oval brooch. Some of this research was done before the science of osteology became well-established, but some publications dating into the 21^st century still use grave goods as the only method of sexing remains. Despite having the knowledge at their fingertips to sex the remains based on well-established osteological markers—sex determination from either the skull or the pelvis—they based their conclusions that Viking invaders/warriors were comprised only of males from a superficial examination of the graves.

However, when the University of Western Australia team went back to actually examine the bones themselves, they determined that a full fifty percent of Vikings buried with weapons were actually women. Surprise!

A hundred years ago, it was not possible to use forensic anthropology techniques to determine skeletal age because the science was in its infancy and wasn’t understood to any great extent. But today, there is absolutely no reason to make gender-biased assumptions instead of stating scientific fact because the research team is only looking at part of the picture. Now, to be fair, sometimes remains are degraded because of age and weathering, but for remains with clear osteological markers, there is no excuse for not completing a full examination. In this case, out of the 14 skeletons examined, 6 were determined to be female, 7 were determined to be male, and only 1 was indistinguishable due to degradation of the remains.

Many saw this result as the battle cry of the Viking shieldmaiden. While the fact that some of the women were buried with weapons isn’t conclusive evidence of those same women fighting on the battlefield, the lack of grave weapons is also not conclusive that a particular woman was not a shieldmaiden. That part of the story is yet to be resolved. However, what is clear is that the current overwhelming view of men as the only Viking invaders of England is not correct. Thanks, forensic anthropology, for clearing that up!

Photo credit: Carrie Morgan

State Police Crime Lab Tour: Ballistics

In this final installment of my tour of the Springfield Massachusetts State Police crime lab, we’re going to cover ballistics. Lieutenant John Crane was our guide through the world of ballistics, which was an eye opener for me and my daughters who are all gun control-loving Canadians. In fact, when we told Lieutenant Crane that we’d barely ever seen guns and had certainly never held one, he immediately handed us several different ones. Maybe not a big deal for the Americans in the crowd, some of whom consider guns a daily part of life, but it definitely was a surreal experience for us!

Ballistics:

• The ballistics division has three primary roles:

1) Respond to shootings, reconstruct the scene, and collect all firearms’ evidence.

2) Test evidentiary firearms.

3) Compare fired items.

• A ballistics officer will go to a victim’s autopsy to retrieve the evidence as it’s removed from the body. This maintains chain of custody.

• The unit responds to all suicides by firearms simply for practice and to learn new ways for bullets to behave inside the human body.

• Springfield has a population of 150,000. There is approximately 1 gun crime/week, and 15 - 20 murders/year are gun related. This number would be higher, but Springfield is home to one of the country’s top trauma hospitals (Bay State) and they save many victims who would likely die in other locations.

• The National Integrated Ballistics Information Network (NIBIN) is the AFIS equivalent for cartridge cases. It helps identify the cartridge, but it doesn’t actually put the gun in any one individual’s hands, so it has limited use.

• There is only a 3% chance of successfully identifying a fingerprint from a gun. It is not possible to pick up a print from the textured grip, only from the barrel or the magazine. But the hot gases produced during firing can destroy the fingerprint and will absolutely destroy any DNA that might be on the firearm.

• The ballistics division has three different ways to test-fire a gun for comparison of either the bullet or casing to the recovered evidence:

1) The snail—a very large metal box with an inner, snail-like curl. The bullet is fired into the box and circles through the curl to fall out, spent, at the end. The bullet gets flattened and is of no use for comparison, but the cartridge pops clear, so this is an excellent method for cartridge matching.

2) The water tank—a ten-foot long metal box filled with water with a firing tube at one end. Bullets up to .50 caliber can be fired into the tank, but hollow points bullets can’t be tested since they break apart only a foot or so into the tank. Otherwise, it’s an excellent firing tool for most handguns. Most bullets only go a few feet into the tank before falling to the bottom. Advice from the ballistics officer, Lieutenant Crane—if you’re being shot at, jump into the nearest body of water because it’s like firing into cement. (Jen’s aside—Mythbusters has confirmed this).

3) The cotton box—an eight-foot long metal box filled with rolled cotton, separated in one-foot dividers of cardboard, and with a firing tube at one end. When a bullet is fired into the box, it spins through the cotton, picking up strands until it becomes enmeshed in a ball of cotton and stops. When the bullet is retrieved, it’s in absolutely pristine condition for direct comparison. This is the only way to test fire hollow point bullets.

• The ballistics officers use a two-headed Olympus microscope with an attached digital readout for performing evidentiary comparisons (see above photo). Lieutenant Crane was kind enough to go through a comparison for us and even showed us the evidence from a fatal shooting just the week before. When comparing evidence, officers like to have two different areas of agreement, but one extremely strong area of agreement will be sufficient if that’s all they can get. A minimum of two people have to check the evidence to agree with the match.
  

All in all it was a fascinating tour and I definitely got some new ideas for upcoming novels. Thank you once again to Detective Lieutenant Holleran, Sergeant Heffernan and Lieutenant Crane for taking the time to introduce us to their real world forensics!

Photo credit: Jack of Spades

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The Seymour Agency’s 1st Literacy Fundraiser:

We at the Seymour Agency are raising money throughout September for #LiteracyMatters. Stop by the agency blog for our auction of great prizes such as signed books, swag, professional editor calls, and manuscript critiques: http://seymouragency.blogspot.ca/; all money raised will go to support the Southwest Florida Literacy Council Gulf Coast. Bidding goes from September 1 – 30, 2014, so don’t miss out on these great prizes. I’m donating signed hardcover copies of DEAD, WITHOUT A STONE TO TELL IT and A FLAME IN THE WIND OF DEATH. And, as an extra bonus, the lucky winner will also get a hot-off-the-presses advanced reading copy of TWO PARTS BLOODY MURDER, which won’t be available to the general public until February of 2015. Want to find out what happens next with Matt and Leigh? Sto by http://seymouragency.blogspot.ca/2014/09/auction-item-36-jen-j-danna-books.html and bid for your chance to find out long before everyone else. So I hope to see you all bidding in September!

State Police Crime Lab Tour: Evidence and Criminalistics

It’s part two of our series based around my tour of Springfield’s Massachusetts State Police crime lab. Today, we’re talking about evidence handling in the lab as well as criminalistics. And stay tuned at the end of the post for some important information on how you can get your hands on an advanced reading copy of TWO PARTS BLOODY MURDER, book five in the Abbott and Lowell Forensic Mysteries, months before it becomes commercially available.

Evidence:

• Most evidence is dropped off by the investigating officer, but some municipal police departments have evidence officers whose job it is to deliver evidence. This can be problematic since the investigating officer is not present if the technician has any questions about the information on the forms accompanying the evidence.

• Once there, new evidence labels are added and detailed to maintain the chain of custody.

• Any drugs that come in are immediately heat-sealed before being stored.

• All evidence is temporarily stored in the evidence room before being sent out to the appropriate lab or testing facility. Case numbers on the box or envelope are in the format of: xx(year)-xxxxxx(case number). Some cases I saw were from ‘80s or ‘90s (cold cases) but most are from 2013 or 2014.

Criminalistics:

• For me, criminalistics was a typical wet lab, and very similar to my own.

• They process clothing, sex assault kits, weapons, all biological samples (i.e. blood, saliva or semen), and gunshot residue. They also carry out blood stain pattern analysis on scene or on evidence brought into the lab.

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  The lab contains a separate room with several alternative light sources. These light sources can be used to visualize human biological fluids like saliva, sweat, semen which all fluoresce. Contrary to most TV crime shows, blood does not fluoresce under alternative light sources. In fact, it tends to darken and be less visible.

• The lab has special test cards to indicate the likely sample type of biological fluids. However this can’t be used for confirmation as there are several well known false indicators. For example, the test for semen gives false positives for mold and feces; while saliva can also be found normally in breast milk and feces.

• Blood is tested in situ in the field by swabbing the substance and transferring it to filter paper. Several chemicals are added; if blood is present, the filter paper will immediately turn blue. If there is no immediate reaction, then the substance is not blood.

• All DNA samples are processed only at the Maynard lab location.

Next week will be the final post in this series as we delve into the science of ballistics. See you then!

Photo credit: JustGrimes and University of Michigan

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The Seymour Agency’s 1st Literacy Fundraiser:

We at the Seymour Agency are raising money throughout September for #LiteracyMatters. Stop by the agency blog for our auction of great prizes such as signed books, swag, professional editor calls, and manuscript critiques: http://seymouragency.blogspot.ca/; all money raised will go to support the Southwest Florida Literacy Council Gulf Coast. Bidding goes from September 1 – 30, 2014, so don’t miss out on these great prizes. I’m donating signed hardcover copies of DEAD, WITHOUT A STONE TO TELL IT and A FLAME IN THE WIND OF DEATH. And, as an extra bonus, the lucky winner will also get a hot-off-the-presses advanced reading copy of TWO PARTS BLOODY MURDER, which won’t be available to the general public until February of 2015. Want to find out what happens next with Matt and Leigh? This is your chance. So I hope to see you all bidding in September!